William m



w. M. BRUCE, JR.

TELEGRAPHY-v APPLICATION FILED MAR. 4.1915. 1,317,859. Patented m. 7,1919.

Q l l l l l l l l l l F amowltoz v mlw VMW L 'a/m 75M 1 7 M WILLIAM 1vr. BRUcEQ R, or srnnvermmi, om'o.

To allwh o m 2'25 may'concem a .Be it knownthat IJ'V LLIAM M. Britten, J12, a citizen of the. United States, residing atiSpringfield in the 'county'of Clarkand.

State ofgOhio, h ve invented certain new and useful Improvements in 'lelegraphy, of

' which the following is a specification;

; My invention relates to 'improvenients in 'telegraphy and particularly relates to means for insuring an even-distribution of current in cables or conductors of high capacity in sending signals so as to get a uniform marking of dots or-dashes, both when the cable is normal or zero and .also when the cable is not fully discharged andztherefore not at zero. 7 i

I have lieretofore-eliiployed a system of. telegraphy in which current reversals are employed Whlch are automatically regulated at the. sendingend s0 thatzcurrent ofdiflerent polarities are impressed upon the a cable or conductor for'the same length of tune to insure the same 7 a rise in potential inthe cable. ductors are be ng. charged and d scharged rapidly in sending a series otsignals, par 'ticularly of dlfierent lengths such as dots and dashes, the cable does not-always reach the normal or zero pointi-betwee 'l such sig- 7 H V lnterval between slgnals, hence the first mpulse .(or current nals as it does after a time reversal) of a series olfi-mpulses, owingto the conditlon of: the cable,1s apt to make a slightly longer character than the succeed-l ing ones if they a re short characters orin case there 1s along ,characterifollowed by" a short character there maybe a slight space between t that; and, the succeeding character; 'due to the sameicause, namelyithat the cable or conductor may'reachnormalor zero in a long interval where 1t does not reach the same zero'bya short interval.

To-this end I provide means for control ling the amount of current impressed on the conductor at the sending end so as tocause the same rise in potential in thel cable when the cable is not completely discharged as occurs when the. cableisflatl zero.

- .In the accompanying drawings the isfa diagram of -circu ts'fand apparatuse1n bodying my nventl'onfi. i

- 1 1 1 3 -said drawings. I have shown appa ,ratusfor'one end of; the cable only,- itbes ing understood that this invention has todo only with thesendingend and itis, of course 7 understoodthat the cable be:properly Specification of Letters Patent.

When cables orhigh capacity con-t might not. retain TELEGRAPHY.

Patented 001:. '7, 1919.

Applioationifiled March 4, 1915. Serial No. 12,083.

equipped with sending and 'receiving apparatus at each end thereofr In the saiddrawings 7c is an ordinary telegraph key cuit with a relay Z2 and a battery fla' to cause the relay Z2 to be operated whenever its cir-. cuit is opened orclosedflat the contact is? The armature a of the relay 70 is connected by; wire 1 to a polarized :sendingrelayb and thence to ground at g. This armature fa or transmitter which is in ciris normally engaged with contact *a? which] is connected by wire '2 to contact 6 0f re lay b and by wire 3 to the negative side of the'main battery B and by branch Wire-4: to a contact 5 of a cut-offrelayc, the other contact 6 of said branch wire 7 to wire-8 and to thefpositive side of the battery B, there being also a connection from through wires Sand 9 to contact a operating relay k contact a 6 armature b ofrelay b is connectedytj the and also by wire '10 to conductor or cable by a circuit overWire-IQ which normally includes resistance 7'. This armature b? is also connected by branch wire 13 to of said relay beingconnected through inductive resistance 1'? to ground at g3. The (Z 1s arranged to receive'the sluggish relay same impulses as the conductor and it may be connected directly into thecircuit, which leads fronrthe armature b of the sending relay 6 to the cable.

connect it in parallel as shown wire 11 and 11 leading from the contacts b and "6 adapted to'be engaged by the armatureb By. this constructionthe relay di -gets a posi 6 engages tive impulse when the armature contacts I)? and b fromthemain-battery B through wire 11 to ground at '9 when the arlnature b engages thecontacts b and [fat gets a negative impulse fromgthe battery B through the contacts I) and 'b and w re 11 to ground at 9 This relay d would work ifit got impulses from oneside only of thearinature b? have it take the impulses from both sides thereof so as to getexactly the same in1 pulsesthat go into the conductor. -'When, however; 1t is connected 'asi shown the draw ng so as to getfirst a positive and thena negative impulse these reversalsof; to neutralize the residual current would tend magnetism n the relay core and the relay its magnetism so readily relay 0 being connected .by'

"this side of the battery of the of the sending relay 6. The

I prefer, however, to

polarizedrelayc, the other side but it is preferable; to i ance 1" is short circuited through wire andcontact 612 in connection with the armature d and wire 14 and as the relay cl will be magnetized as the first impulseis fed to the cable this first impulse will pass through the resistance r and any succeeding impulsewill pass through the short circuit formed ,by wires 14, contacts (Z and (Z and wire 15' provided the relay cl remains energized; This relay (Z is so constructed that it will remain energized so long as the impulses foll'o'weach other in fairly rapid succession, but if a time interval is allowed to lapse between impulses sufficient to bringthecable to zero, the relay (Z would be deenergizedand the succeeding impulse would pass through the resistance or other obstruction placed in the circuit at 1'. It will lie-under stood that while I have shown ordinary resistance at 7", any formof obstruction may be used at that point which will modify the current fed to the cable to the different conditions of the cable due to a complete discharge or only a partial discharge, there. WVhile I have shown an operating relay 70 in circuit with the key 70 and battery 70 it is obvious that the key might be substituted for the armature a of the relay is, so as to play between the two contacts a and a in. which case the battery 70 and relay 76 may i be dispensed with.

The operation of the system is as follows: On pressing the key is a positive impulsewill be sent from battery 'B to the sending relay 1) from the positive pole of the bat.-

tery B, through wires 8, 9, contact a armature a, wire 1, relay 6 and ground at 9; it being understood that the armature a will be caused to engage contact a by the energizing ofthe relay 70 from the battery 70 This will cause the armature b of the sending relay 1) to-engage contact 6 and positive battery will be fed through wire 10, contact bfiannature 6 wire 12 and resistance 1' to the conductor or cable. The relay 0 will? also get current'through branch circuit 13 from wire 12 but owing to the inductive re sistanced 'will operate at an interval of time later than the relay 6. This will cause the armature 0, ofrelay c to move from contact 5 to contact 6 and thus cut off the supply of positive current by grounding the positive side of the battery at 9 The relay (1 being in. a. parallel circuit formed by the contacts b and 6 wire 11F to ground through one Winding of the relay 01, this relay will be energized, by the same impulse of positive current emanating from battery B and flowinginparallel to the cable and to the relay. When relay d is energized the resistance 0" will be shunted out of the main conductor circuit and will 'be held shunted so long as the relay d remains-energized. If, however, the armature c of the cut-off relay 0 should remain for s-uflicient period on the contact 6 so that the cable would be completely discharged, the relay oil would have had time to be completely d'eenergized and open the shunt at-d thus leaving the obstruction r in the conductorfeeding circuit. This could onl'y'happen in making-a dash of sufficient length to let the cable getback to zero. Since I the cut-offrelay 0 works automatically the cutting-oil'the current and the-deener gizing of the-relay dwill occur even though the key remain depressed and armature a in contact with a Ifthe current is broken at the key A so that the armature it moves to'the-back contact a the polarizedlsending relay isenergized" by a currentof opposite polarity and it's armatureb engages con-' tacts b and b*- and a negatlve impulse is impressed on the cable through wires3 and 2, contact. 5 armature b and wire 12' as before. The-relay (I will also get the same negative impulsethrougl' the parallel circuit from contact bflwire 11, the other winding of the relayto ground" at 9 thusagain energizing the said relay. Now, if these posi" tive andnegativeimpulsesfollow each other with sufficient rapidity the relay :51 will remain energized and the obstruction T will be shunted from the circuit so long as a rapid succession of impulses continues. \Vhenever the key remains at rest for a suflicient period in either'position the relay (Z will be.

deenergized? by the cutting olf'of its current supplyby the cut-ofi' relay c and when this current supply is cut-ofifor a sufficient interva'l of time to permit the sluggish relay to release its armature the obstruction 1 will remain in the sending circuit to the cable or conductor; The resultof the arrangement is that if positive and. negative impulses follow each other with sufficient rapidity to cause the cable to retain a p'ortion'of the previous charge there will be fed to the cable a slightlylarger charge of the opposite polarity at the next impulse so asto compensate for the residual charge to be overcome and thus. produce an equal rise of potential within the cable for each impulse as for the preceding one: The relay d being so" adjusted that "the. time interval during which it will hold up its armature after its circuit is broken is equal to the time interval necessary for the cable to be completely discharged, it Wlll be seen that the rise in p0- tential in the cable itself for each impulse will be the samewhether itis an initial impulse (when the cableis completely discharged) or a succeeding impulse (when it is not completely. discharged); s

. I have found that it is possible under certain conditionsito do away with the resistance o entirely by. .having the relay d so adjusted that it will close its contacts at a slight interval after-the impressing of an impulse upon the feed wire 12 in which case a portion only of the first impulse. will be fed to the cable and this adjustment could be made so that a suflicient part of the first impulse would pass to the cable from the feed wire 12 to produce the same potential rise in the cable, when atzero, as by the succeeding impulses when the cable is not at zero, that is, the relay d would operate at a time interval after the operation of the P relay 6 to cause only a portion of the current impressed on the wire 12' at the first impulse to pass into the cable by reason of the gap at the contact d at the beginning of the impulse which would be closed by the firstimpulse in time to secure the feeding of a proportional amount of said impulse to cause the same rise in potential as by the succeeding impulses. It will be understood in this case that all. of the impulses will pass through the feed wires 12, 14: and 15, but owing to the initial break in this feed circuit the first impulse made by the relay 6 would be fed to the cable through a slightly less time interval than the succeeding impulses. V V

The arrangement with the resistance or some similar element 1' is considered preferable as it avoids the delicate adjustment. of the relay to secure the result when this ,resistance is not used.

In the figure I have shown a modification in which a battery is used to keep a small charge on the cable at all times when it is not in use. This battery is so regulated that the charge thus assigned to the cable is equivalent to the residual charge which will be found in the cable after each impulse of a certain polarity and in order to make it effective the charge which is at all times on the cable is of the opposite polarity from that of the last impulse impressed thereon. In connection therewith'I provide a slow relay which is adapted at the. first movement of the key to cut out this battery which is normally onthe cable and cut in the battery which supplies the impulses so that the first impulse impressed upon the cable finds the same conditions as the succeeding impulses and in this way the efiect of impressing the impulses on a cable which is com.- pletely discharged is obviated and all the impulses will find exactly the same condition in the cable whether they are at the end or the beginning of the series, or part of a continuing series. In this connection it. will be remembered that the reason for the distortion of a character at thebeginning of a series of impulses is due to thefact that there is a certain amount of residual charge in the cable when a series of impulses are following each other in rapid succession, and the means which are heretofore described for overcoming this is to give to the first'impulse a slightly higher resistance through which it passes or to cause it to be-impressed upon the cable for a slightly shorter time in order that it may not cause a higher rise of potential in the cable (due to its wholly discharged condition) than when it follows along in a series and meets residual charge in the cable.

In the figure of the drawings, the slow relay (Z is shown in multiple with the operatingrelay connected directly to the key, and therefore receives its impulse and operates to cut off the feeding battery B before transmitting relay operates to transmit the impulse into the cable. The feeding battery B is shown connected to a back contact (5 of the slow relay (Z whose armature (Z is connected directly to line 12 leading to the cable, variable resistance 7 being interposed between the battery and the back 0011- tact, d by which the amount of battery fed to the cable when idle can be regulated to correspond to the residual charge which would be in the cable after an impulse or a series of impulses. This adjustment can readily be ascertained by making impulses both after a pause and in series until the result desired is obtained. The armature of the transmitting relay b is connected to the front contact (Z on the slow relay (Z so that when the slow relay operates it connects the transmitting relay direct to the cable and cuts off the feeding battery. Of course so long as the impulses from the keys follow each other in rapid succession the slow relay will be held up and the feeding battery will be cut off.

Having thus described my invention, I claim:

1. In a telegraph circuit, an operating key and means operated thereby for impressing current impulses of opposite polarity therepulses of opposite polarity are impressed upon a conductor by means operated by a single key, a feeding battery of one polarity normally connected to said conductor so as to charge said conductor with a polarity opposite toithe last impulse transmitted thereto by said key, and a relay controlled by said key so as to 'cut off said feed battery when an impulse of opposite polarity is to be transmitted thereto, sulostantially as described.

3. In a system of telegraphy, the combination with two polarized relays interdependent and cooperating so that one of said relays cuts oii the current supply for the other and to a conductor whereby current impulses of opposite polarity are impressed upon said conductor for a definite period, a feeding battery normally connected to the conductor so as to supply a charge thereto of opposite polarity from the last impulse impressed thereon by said polarized relays, and a cutofl relay operated by said key to cut 0H said feeding battery upon the first operation of said'key, said cut-.ofi' relay being} sojoonstructed as to remain energized-l so long. as the key operations follow each other in rapid succession and thus retain the feeding battery out of circuit with said conductor and so long as said impulses ane following each other with a predetermined speed; and to cut in said feeding" battery upon a predetermined interval between a series of impulses as and for thepurpose specified.

In testimony whereof: I have hereunto set my hand this 6th day of February, 1915.

WILLIAM 1M- BRUCE, 1;-

can of h n patent ay be obtained for fi e t ac b ad smnz the "emphas se: ct; intents,

Washington, D. 0, 

